Help me out guys. I just replaced my alternator and immediately, the car won't start. No lights, fob doesn't work, nothing. Checked and rechecked all connections and fuses. Everything seems fine, except for the car working part.

 

Charge your battery...


or replace it

 

Brand new Red Top reading 12.78 volts. Changed that too.

 

check all your grounds and make sure they're tight and terminals.

 

Did all that too. Many times.

 

well you're missing something...


I still think it's related to battery.

 

Here's the thing though. Nothing under the hood was touched except the alternator connections. The harness plug and the ground, that's it.

 

Wait... you didn't unplug your battery while working on it..? you may have fried something if it shorted.

 

so, can you get power in your car? lights, horn ??

 

No power, no nothing.

 

What could've possibly fried by unplugging the harness and disconnecting the ground to the alt?

 

shorted/drained the battery if the positive cable touched a ground.


There's a main fuse, did you check that one?


I mean we're trying to help you troubleshoot here over the Internet but per the words of a great wise crab, "You have to be our eyes and ears and hands".

 

No, I totally get it and I appreciate the help.

I'll check all the fuses again.

 

hmmmmm....no power via lights or horn, but battery is showing 12.8 volts....

silly question; are the battery terminals connected?

I'm not an electrical engineer, but I play one on t.v. so, I have no clue what I'm doing, but thoiboi's suggestion of shorting out sounds plausible.

 

Does the TL have a fusible link in the main battery cable leading to the fuse box?

 

Did you check fuses?

 

Checked all the fuses again. All are fine. I also checked voltage at the main harness plug under the hood by the washer fluid filler, 12.54 volts. No clue.

 

Not sure. I'll try and look it up.

 

Also, I have voltage at the under hood fuse box.

 

my book is packed away otherwise i would try to point to a specific fuse.. but the only other thing i can think of would be to put your old alternator back in to see if u get juice to everything.. i mean since u say the batt is good and fuses are good and all connections are good. but hope u didnt reverse the + and -

 

Just to throw this out there


Check the fuse where the cable comes from the battery to the fuse box. There's a fuse there held on by screws. See if power is getting past that fuse.

 

Thanks for the input. But serious question. Where would I have reversed the + & -? The only 2 connections on the alt is the ring terminal cable and the harness connection. No way to reverse them. Battery terminals were/are correct.

 

Thanks. I unscrewed all the larger fuses and tested them for continuity. All good. I have power all the way across the fusebox.

 

Only thing I can think of is bad alt. I'll change it back this weekend.

 

that is very possibly true. I have never replaced the alt, nor looked at the schmatics nor looked at it on the car. But yes I agree, the alt might not be good if everything else is right.. otherwise, check fuses.. it might be one inside too. I have no idea. I dont have my book.

 

I am an electrical engineer, but I play a car mechanic on the interwebs

Seriously, it troubles me greatly if you didn't disconnect the battery when you were swapping out the alternator. Any number of momentary shorts or surges could have occurred. Also of note is that the service manual states very clearly to disconnect the (+) battery cable then the (-) battery cable at the start of the job and then at the end of the job to connect the (+) battery cable then the (-) battery cable. This same process is also references here repairpal.com/alternator-replacement under "Things to Be Aware of When Replacing the Alternator". This is distinctly different than the typical "just disconnect the (-) cable you see for many other jobs.

My gut, "tea leaves", and "executive 8 ball" all lead me to believe you did something very, very, bad by leaving the battery connected. Even so, a completely dead car isn't what I'd expect.

Did you check Fuse 22(120A) and Fuse 23(50A)? in the under hood fuse box? Those are in line with starter and alternator but if you shorted something bad enough to pop those bad boys I think you would have known it.

If you did disconnect the battery and I just missed it in the thread then disregard to above.

Also, if you changes the battery at the same time you changed the alternator then there exists the possibility that the new battery is a dud. So maybe try out the old battery of you still have. This is unlikely though since I would expect you'd still get some lights but no start as typical "dud" will have voltage but not be able to source enough current for much other than dash and interior lights.

 

Thanks for all the input guys. I am a complete idiot. I blew the f@#king main 120A fuse. Somehow I didn't notice the first 2 times I checked it. Yes 2 times. But it IS definitely blown. Thanks again for all the help and scaring the crap out of me with horror stories. Thankfully, it's a $6.33, in stock item. Sorry for wasting everyone's time.

 

No worries. We partake in all this voluntarily

But a 120A fuse...like an arc welder..surprised you didn't know exactly when that popped!

 

thankfully that fuse in there in case something like this ever happens.

 

LOL, seriously......

You must have been welding pretty good with a wrench or a screwdriver to blow a 120A fuse!

 

Yay for fuses taking the hit for our mistakes! main fuse.


Glad you figured out the problem!!



And next time, unplug battery when working with anything electrical!!

 

recently changed my alternator as well battery light stays on car has power horn and lights work what may it be??

 

Battery light means the car is detecting an issue with the charging system. Check that all wires were installed properly. to the alternator. Is the voltage 14.4 with the car on and running? Most aftermarket alternators do not work well with honda/acura products or fail very quickly. Best bet is a denso rebuilt one from rockauto.

 

okay I’ve been stuck with this problem for 5 months lost a very important job due to it I’m about ready to run her across the scale